<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>

<body>
<button>点击停止定时器</button>
<script>
    var btn = document.querySelector('button');
    var timer = setTimeout(function () {
        console.log('爆炸了');

    }, 5000);
    btn.addEventListener('click', function () {
        clearTimeout(timer);
    })
</script>
</body>

</html>
